Which Indirect Value of Biodiversity Will Have the Greatest Economical

Which indirect value of biodiversity will have the greatest economical value to people?

A) a twenty-hectare marshland that acts as a sponge for rainwater
B) the ecotourism market in the United States
C) two hundred hectares of wetlands in Canada that soak up pollutants and purify water
D) forests that decrease erosion along the banks of rivers in the Philippines
E) a row of trees that act as a wind block on the northwest side of our homes, decreasing our need for air conditioning and cooling systems in the summer